If you have Windows 10 N or KN then you may not have the Media Feature Pack installed. https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows

Hello FredMcD,

I do not have a N or KN version of windows so when i attempt to run the Media Feature Pack I am notified that it isn't applicable to my computer.

https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues

Does it make a difference if you select a lower quality setting or change the viewport dimensions ?

cor-el said

Does it make a difference if you select a lower quality setting or change the viewport dimensions ?

It does not

Are there media related messages in the Web Console?

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en-US/Tools/Web_Console

FredMcD said

https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues

I've reviewed these steps and checked the ones that are applicable to my situation (not going to use Flash though so didn't try that step) and am still experiencing the issue.

I really do appreciate the assistance you have provided so far.

cor-el said

Are there media related messages in the Web Console?

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en-US/Tools/Web_Console

Not seeing anything media related

With uBlock enabled:

MouseEvent.mozPressure is deprecated. Use PointerEvent.pressure instead. base.js:1129:359 Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://googleads.g.doubleclick.net/pagead/id. (Reason: CORS request did not succeed).

method `updateReduxProperties` not defined desktop_polymer_v2.js:7269:150 Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://googleads.g.doubleclick.net/pagead/ads?cust_gender=1…=u&rsz=%7C%7Cn%7C&dssz=39&icsg=67108863&mdo=0&mso=0&lact=476. (Reason: CORS request did not succeed).

Loading failed for the <script> with source “https://static.doubleclick.net/instream/ad_status.js”.

Without uBlock enabled: MouseEvent.mozPressure is deprecated. Use PointerEvent.pressure instead. base.js:1129:359 method `updateReduxProperties` not defined desktop_polymer_v2.js:7269:150 Loading failed for the <script> with source “https://static.doubleclick.net/instream/ad_status.js”.

I do appreciate your help with this issue.

Alright so I tried the videos on Edge and Chrome and had the same issue which made me believe it was something in Windows itself. I reinstalled Windows 10 and have solved this problem. Thank you FredMcD and cor-el for assisting but you can only do so much against Windows and its, fun behavior.

So true So true

It is possible that some other software was keeping a handle on the sound device preventing Firefox from playing the sound.

If it happens again then check whether other application are playing sound and possibly close and restart Firefox to refresh the audio driver initialization.

cor-el said

It is possible that some other software was keeping a handle on the sound device preventing Firefox from playing the sound. If it happens again then check whether other application are playing sound and possibly close and restart Firefox to refresh the audio driver initialization.

As I was reinstalled programs after the wipe the problem came back. I have narrowed the issue down to the "Asus Armoury / Aura Sync" program, removing those programs returned sound to the youtube video. I have started a support ticket with Asus to see what the cause is.

That was very good work. Well done.